The present invention relates generally to collision detection systems and countermeasure systems. More particularly, the present invention relates to a system and method of adaptively adjusting collision load paths of a vehicle for vehicle collision compatibility during a collision event.
Various sensing systems currently exist for performing collision detection and countermeasure system operations. These operations can include collision and object detection, as well as object classification, tracking, and relative distance and velocity estimation. The stated operations may also include the rotation of vehicle wheels or collapsing of a steering system to adjust vehicle stiffness during a collision event.
Collision detection, warning, and countermeasure systems exist in various passive and active forms. Some countermeasure systems are used to aid in the prevention of a collision, others are used to aid in the prevention of injury to a vehicle operator. The countermeasure systems may provide a vehicle operator knowledge and awareness of vehicles and objects that are within a close proximity of the host vehicle to prevent colliding with those objects. The countermeasure systems may activate various restraint systems. The countermeasure systems may also adjust vehicle stiffness in order to modify the amount of energy absorbed during a collision and thus prevent or mitigate an injury to a vehicle occupant.
In vehicle frontal collisions, vehicle occupant injuries depend upon a number of factors, such as the mass, stiffness, velocity, and heading, of the host vehicle and the object collided therewith, as well as the effectiveness of any occupant restraint systems. Whether the object being collided with is for example, a large rigid object, a small deformable object, a pole, a pedestrian, an animal, a motorcycle, or other object has a significant affect on the occurrence and degree of occupant injury. When the host vehicle is involved in a head-on collision with an object, the collision type, namely whether the collision is a full overlap or a partial overlap collision, also has a significant effect on the nature and magnitude of the occupant injuries.
Front-end vehicle structures and occupant restraint systems are generally developed to provide optimum protection to the vehicle occupants under a number of different scenarios. The vehicle structures and the restraint systems are designed and tuned to provide protection for unbelted occupants at low speeds and for belted occupants at high speeds. Also, the vehicle structures and restraint systems are developed to provide effective occupant protection under angular and offset collisions. Offset collisions may involve different overlaps with both rigid and deformable objects.
Currently, a vehicle front structure is designed to have a particular stiffness. The term “vehicle front structure” refers to the portion of the vehicle forward of the occupant compartment. This stiffness exists independently of the traveling speed of the vehicle and the relative speed of the object collided therewith, as well as the type of object involved in the collision and the collision type.
In general, increased front structure stiffness results in higher energy absorption at higher collision velocities, and consequently results in lower occupant injury numbers, such as lower head injury criterion (HIC)s numbers and chest deceleration values. Although an increase in structural stiffness can improve energy absorption during high velocity collisions, an increase in structural stiffness can result in uncollapsable structures at low speeds. The inability of the structures to collapse at low speeds can result in the transfer of increased forces to the occupant compartment and thus the vehicle occupants.
Current collision detection, warning, and countermeasure systems are limited in their ability to adjust stiffness of a host vehicle front structure and are incapable of accounting for various host vehicle and object traveling speeds, object types, and collision types. Thus, there exists a need for an improved collision detection and countermeasure system that provides improved stiffness compatibility for various collision event situations and conditions.